Stitching machine



July 29, 1947.

W. R. SPlLLER El A L.

STITCHING MACHINE Filed Jan. 14, 1943 3 Sheets-Sheet i y 1947- I w. R.SPILLER ET AL 2,424,711 J STITCHING MACHINE Filed Jan. 14', 1943 sSheets-Shef. 2

Patented July 29, 1947 STITCHING MACHINE William R. Spiller and RobertJ. Niederhauser, Dayton, Ohio, assignors, by mesne assignments, to AcmeSteel Company, Chicago, 111., a corporation of Illinois ApplicationJanuary 14, 1943, Serial No. 472,316

19 Claims.

This invention relates to wire stitching mames.

ft is the principal object of the invention to 'ovide a wire stitchingmachine adapted to .rm flat, tight-fitting stitches in hard materialsuch as sheets of metal or the like and having long life and freedomfrom excessive wear in the stitching of such material.

It is a further object to provide such a machine in'which the partssubject to severe wear in use are constructed for maximum life andarranged to be quickly and easily replaced when necessary without theuse of specia1 tools or equipment.

It is a further object to provide for easily and readily adjusting theposition of the clincher mechanism in order to locate it in preciseposition with respect to the location of the stitch and to securelyretain the parts in such adjusted position.

It is a further object to provide a construction in which adjustment maybe readily made for stitching materials of different thickness with-1:-=.it disturbing the driving connections as estabnihed for theactuation of the clincher mechanzsm.

Other objects and advantages will be apparent from the followingdescription, the accompanying drawing, and the appended claims.

In the drawing:

Fig. 1 is a view in side elevation of a stitching machine constructed inaccordance with the present invention with certain parts being brokenaway to more clearly show the construction thereof;

Fig. 2 is a horizontal broken sectional view looking downwardly on theadjustable ways which provide for vertical adjustment of the clincherarm;

Fig. 3 is a broken view of the outer end of the clincher arm showing theclincher mechanism;

Fig. 4 is a view on a somewhat larger scale of the die holder and thedies, being shown partially in section and partially in plan;

Figs. 5, 6 and i are three elevational views looking toward the frontface of the dies and clincher plunger assembly and showing threesuccessive stages in the formation and clinching of the stitches,certain parts being broken away;

Fig, 8 is a side elevational view of the clincher plunger itself;

Fig. 9 is a view partly in plan and partly in section showing a modifiedconstruction of clincher assembly;

Fig. 10 is a broken front elevational view of this modifiedconstruction;

a base portion Fig. 11 is an end elevational view of the die of Figs. 9and 10; and

Fig. 12 is an end elevational view of the clincher plunger.

Referring to the drawing which discloses a preferred embodiment of theinvention, the machine is shown as having a main frame including iii, anupwardly projecting pedestal H, and an overhanging head i2. The drivemotor 14 is mounted in the rear portion of the head and has a suitabledriving connection to the main shaft 15. Shaft 15 extends through thehead to the front, part thereof where the mechanism for forming anddriving the stitches is located, the position thereof being indicated byreference numeral iii. A coil of wire IT is mounted in a convenientlocation on the head and the wire feeds into the stitch formingmechanism in the usual way where it is formed into an in verted U-shapedstitch, the two legs of .the stitch being driven downwardly into andthrough the work material received beneath the head.

An arm 20 is provided on which the work is received, such arm alsocarrying the clincher mechanism which provides for clinching the twolegs. of the stitch after they have been forced through the workmaterial and flattening the legs upon the face of the material. Both thearm and the frame are of sturdy construction being preferably formed asrelativel heavy castings, to provide a rigid structure having a minimumof deflection under the loads encountered in use. Arm 2%) is adjustablycarried on the pedestal, and is so mounted as to have verticaladjustment thereon to accommodate work material of different thickness,and also is arranged to have lateral adjustment to properly center theclincher mechanism with respect to the location at which the stitch isformed.

To provide for obtaining such adjustment the face of pedestal II isformed with the spaced ways 22 and with vertical bearing surfaces 23against which corresponding surfaces of the arm are adapted to bear. Thearm is formed with rearwardly extending projections 24 within whichthere are mounted studs 25 having engagement with wedge shaped gibs 28adapted to bear against the ways 22, respectively, end plate 21preventin lateral displacement of the gibs. By suitably adjusting thestuds 25, it will be evidentthat the entire arm can be shifted laterallyfrom one side to the other while still maintaining its firm support uponthe ways, and when so adjusted and with the wedges again tightened itwill be securely retained in such adjusted position, Preferably threesuch sets of bolts 25 are located in vertically spaced relation on armto provide maximum security and accuracy of positioning. It will beclear also that with the bolts spaced vertically as shown, it ispossible to loosen the uppermost while tightening the lowermost, andvice versa, and in this way rock the arm about its longitudinal axis asmay be necessary to maintain it level and parallel with the formingmechanism.

In order to secure vertical adjustment in the location of the arm whileat all times maintaining the arm in desired level horizontal relation,the arm is provided with ,apertured portions adjacent its inner endwhichare adapted toreceive locking bolts 3! threadedly received in theface of the pedestal l I, and extending through enlarged slots 32 in therear face of the arm at the upper part thereof. The enlarged slotspermit adjustment both vertically and laterally and the bolts at the topof the arm take the load in tension and support ,the arm firmly. A pairof downwardly projectin lugs 34 is provided on the lower face of the arm20 and a connecting pin 35 having a threaded part 36 is secured thereto.A pair of nuts 31 are threadedly received on pin 3'6 and are located onopposite sides of an abutment '38 secured to the face of the pedestal.Thus it will be apparent that having first loosened bolts 3!, the entirearm may be raised or lowered upon the pedestal to adjust the position ofthe arm to a different level by suitably adjusting either the upper orthe lower of the nuts 31. The nuts 31 and bolts 3| are then againtightened to securely lock and retain the arm in adjusted position.Since it is desirable to have as little movement of the arm as possiblein the course of the stitching operation, the gibs 25 are preferably setup to such an extent that they tightly hold the arm and preferably withsufiicient frictional force to prevent downward movement thereof underthe action of gravity. The arm can however be readily actuated either upor down by the means described above, and thus adjustment is simplifiedwhile at the same time maintaining firm and secure support for the armthroughout its operation. Suitable indicating and index means may beprovided as desired to facilitate the setting of the arm.

The clincher mechanism is located at the outer end of the arm andcomprises a die holder or block 40 suitably positioned in a recessedpart of the arm and attached thereto by means of bolt 4!. The positionof the clincher mechanism lengthwise of the arm may be accuratelydetermined by means of a-threaded bolt 42 which bears against theupright face of the recessed portion as clearly shown in Fig. 3. Inorder to adjust the position of the, clincher mechanism in directiontherefore it is; only necessary to; loosen. bolt 44 andmakesuitableadjustment in. theiposition of bolt 42, following which. bolt ii-isagain tightened to retainthedie; block in properly adjusted position.-The die blockis reslr dw ib n nd; g ided; at ach side. by t e testes-1arm; and sts'a i i s lower side di-- i qi Qilz m 2.6.:s0, hat t i firmland securely heldin prope fired.- s ioning w e so ad rises-.1

ha ic. loc r s ormer-1., witnl central upwardly extending portion; 44,at its forward; end and tgn osi e. ides re f; isformed with out.-

r new n rmortions which ontheir rd-faces are suitably-recessed; aclearly;

4 shown at 46 in Fig. 4. Within these recesses there are received,respectively, the two cooperating die members 48, the dies beingthemselves bored and counterbored to receive attaching bolts 49 whichthread into the arms 45 and thus detachably secure the dies in positionupon the die block. In such position the dies are securely held againstany movement by reason of the formation of the recesses in the die blockat the sides and the arm 20 providing support from below.

As shown in Fig. 4, the opposing faces of each of .the dies 48 areformed with a groove or slot 50 which extends throughout the full heightof the die. This groove or slot has a width closely conforming withthediameter of the wire, being preferably only slightly larger than thewire diameter to'provide for receiving the ends of the legs of'thestitch with only a limited clearance therefor. It will be understoodthat with the leg received within the groove in the die, the stitch isguided and supported around substantially the entire outer half of itsperiphery. The portion of the slot below the tapered portion isrectangular in section as shown in Fig. 4.

As shown in Figs, 5, 6 and 7 the slot 50 itself is of less extent thanthe outside length of the stitch, but the upper or leading end of theguide slot is beveled or tapered andis semi-circular in section asindicated at 52 and this taper is such that the opening-at the top ofthe slot is of sufiicient extent to initially receive the advancing endsof the legs of the stitch, and to guide the legs inwardly producing aninward inclination thereof. As a result of the inward inclination in thelegs of the stitch so produced, the clincher in the course ofitsoperation completes the bending and flattening of the legs againstthe face of the material.

lhe actual extent of this taper has been found to be important sincewith too small a taper, the legs will not be bent in sufiiciently to beflattened by the plane top surface of the plunger. Thus where theinclination was such as to provide a taper less than about half the wirediameter, it was found that in many cases the operation of the plungerwould cause the ends of the wire to be doubled back upon itself, ratherthan bending the legsinto a flat clinch relation. On the other handwhere the taper was greater than the wire diameter, an objectionablecondition of curl was obtained in the legs themselves, and it wasdifficult to flatten the legs into a tight clinch against the surface ofthe material and there was some cndency to spread the hole inwardly asthe wire was clinched. Best results have been consistently obtainedwhere the extent of the taper was' less than the leg diameter, butsomewhat greater than half the leg diameter. It will be understood,however, that with different types of material to be stitched, and withwire of difierent modulus of elasticity and tensile strength, somechange in these relationships may be effected.

The dies are subject to substantial wear in the vicinity of the taperedgroove, and for the purpose'of securing the maximum of wear from eachpair of dies, they are made symmetrically at opposite ends so that byinverting and switching the dies to opposite sides of the die block,they may be reassembled with a new tapered slot and thus the effectivelife of the dies is substantially doubled.

A clincher plunger 55 is arranged for travel in a reciprocating path ofmovement in the two guide slots 50 formed by the'opposing die members,the plunger being of substantially the same thickness as the diameter ofthe wire and havin a width corresponding to the extent of the slot 50and hence such as to fit closely within the guide slot while beingfreely movable therein. To provide additional strength and stiffness,the plunger is formed with a front portion 56 of less width than therear portion, such front portion moving freely in spaced relationbetween the two side faces of the dies themselves. This front portion 56preferably projects upwardly above the clincher surface 51 a distance ofabout half the wire thickness so as not to strike and deface the surfaceof the work, forming a forward retaining edge 58 as shown in Fig. 8which serves the purpose of guiding the ends of the legs into thedesired flat relation and preventing forward movement thereof during thecourse of the clinching operation. Preferably the clinching surface 51is' plane lengthwise of the stitch and is grooved transversely as shownin Fig. 8 with a curvature corresponding closely with that of theperiphery of the wire to receive the wire therein and to provide foradditional guiding of the wire during the clinching operation. Both endsof the plunger are similarly shaped, and because of the severe usage towhich it is subjected it is provided with a pair of equally spacedapertures 59 so that it can be assembled in either of two relatively inverted positions affording additional life and wear. Backward movementof the wire is prevented by the front face of the die block itself andthe wire is thus completely guided in all directions.

,For the purpose of actuating the clincher plunger, the drive shaft isprovided with a cam 69 which actuates a connecting rod 6!, such rod inturn operating a ball crank lever 62 pivotally supported at 63 on frameH. The opposite end of the bell crank engages a push rod 64 which ismounted for movement in a substantially longitudinal direction in theframe, and projects parallel with the arm 2!! and into a positionadjacent the inner end and below the working surface thereof. Armcarries a push rod 65 supported in extensions formed in the lower sideof the arm and in a protected position beneath the working surfacethereof, push rod 65 being parallel to and having abutting engagementwith the end of rod 64. In order to provide for maintaining theoperative relationship established between the two rods 64 and 65throughout the extent of the vertical and lateral adjustment of the arm29, one or the other of these rods is provided with an extended bearingsurface so that proper engaging relation is maintained notwithstandingrelative travel of the arm and its rod 65. In the form shown, rod 84 issufficiently large in diameter so that it will have proper drivingrelation with rod 64 in all relative positions thereof.

Suitable means are likewise provided for adjustment in the extent ofmovement of the clincher plunger and in the upper elevation which itreaches, to determine the force with which the plunger bears against theclinch, and the extent to which it is flattened against the work. Suchadjustment can be incorporated at any suitable point in the clincheractuating mechanism and the adjustment may be made accessible eitherfrom the rear of the pedestal or from a protected position beneath thearm. In the arrangement shown, the rod 65 terminates in a butt end, andan intermediate connecting rod 58 is mounted coaxially therewith andsupported in the web portions 69 of the arm 20. A bolt 10 having a headH is threaded into a recess in the end of connecting rod 68 and a locknut 12 provides for moving the head of the bolt closer to or fartherfrom the end of push rod 65. It will be obvious that in this way theeffective length of the connecting rod 68 is altered and such changecauses a greater or less travel of the clincher plunger.

Having secured the proper adjustment of the clincher plunger operation,the arm 28 may be then reset for work of different thickness, andnotwithstanding the raising or lowering of the arm, it is not necessaryto readjust the operation of the clincher plunger, as it retains itssetting and will provide for making the same type of clinch on the newwork as on the work of different thickness, this being a distinctadvantage where work of different thickness is being handled.

In the outer end of the arm2il there is mounted a pin 75 which serves asthe pivot for a bell crank lever 16. The lever is notched out as shownat 11 and receives the forward driving end of the connecting rod 68,such rod when moved toward the left in an operating stroke of movementcausing a rocking of the bell crank in a clockwise direction as shown inFig. 3. The bell crank also is formed with a downwardly extending yokeportion '58 which is adapted to be received in the rear of a pin 19 alsocarried by connecting rod 68 to provide for reverse rocking of the crankin response to the opposite travel of the connecting rod.

Projecting from the other side of the crank 76 is a round pin 80 whichis received within the lower aperture 59 of the clincher plunger whenthe plunger is assembled in the groove in the dies. It will thus beclear that in response to travel of the connecting rod to the left inFig. 3, motion will be imparted through the bell crank and the pin 80 tothe clincher plunger to lift the same upwardly in a stroke of clinchingoperation while the plunger is guided by the guide slots 5?). Returnmovement of the connecting rod is obtained under the action of acompression spring 82 one end of which bears against the web element 69,and the other end against a collar 83 secured to the connecting rod 63,and provided with a suitable handle 84 readily accessible beneath arm20,

Because of the severe wear upon the clincher plunger, it is usuallyfound necessary to remove and replace this part at somewhat frequentintervals. In accordance with the present invention this is accomplishedwith great ease and without the necessity for disassembling the dies. Itis only necessary to grasp the handle 84 and to pull the connecting rod68 forwardly against the action of spring 82, to a point such that thebell crank is rocked beyond its normal range of operating movement andinto the dotted line position shown in Fig. 3 where as will be clear thepin 80 is withdrawn from aperture 59, providing for direct downwardwithdrawal of the plunger 55. Similar action provides for the reassemblyof eitherthe same plunger in inverted position, or another plunger, theplunger being inserted in the guides 50 with the bell crank manuallyrocked into the dotted line position and the handle then released withthe pin 80 returning into engaging relation in the lower of theapertures 59. While it is possible also to remove the bolts 49 and withthem the two die members 48, such operation is preferably followed onlywhen it is desired to remove and invert or replace the die membersthemselves, such operation ordinarily not being required as frequentlyas. replacement; of the plunger. a Y

.It is usually found that with stifi and hard metal sheets such assheets of Duralumin used in the fabrication of airplane partsforinstance, the resence of the dies surrounding and giving support to theouter half of the periphery of each leg of the stitch results in a cleanhole being punched with little tendency to enlargeor tear out the hole.As the legs of the stitch are forced into the stiff material, the endsthereof tend to act as punches forcing a chip or slug of the metal inadvance of the wire and discharging it downwardly through the opening.inthedies, chips usually cling to the-material on the inside of thelegsof the stitch and if desired means may be provided for facilitatingthe removal of such chips so that they will not be caught beneath thelegs of the stitch. For this purpose the die block is cored as shownat80 and connection is made to a suitable source of air pressure. Thepassage 90 communicates with a pair of upwardly extending passages 9 Iformed in the part 44 of the block, the passagesSI opening on thefront'faceof the block as shown at 92, immediately adjacent the insideof the legs of the stitch, at the points where the'chips usually tendto-cling, Suitable valve means may be provided for controlling the airsupply to have it in operation as the stitch is being'formed, suchmechanism being conveniently controlled from the trip mechanism whichplaces the machine in operation.

With somewhat softer sheetmaterial there is some tendency for thedownwardly moving stitch todraw the metal, and this condition is alsonoted more particularly where three or more sheets are being stitched.In the latter case, and particularly where the intermediate sheet orsheets is of softer materiaLit-has been found that the stitching actionresults in drawing the metal of the intermediate sheet or sheetsdownwardly with the stitch, providingafirm and secureinterlockingof thatsheet with the next lower sheet, thereby forming anextremely tight andsecure connection.

- In operation, the drive motor actuates the shaft I in response tobeing tripped, preferably by a manual trip control in the usual manner,causing thestitch forming mechanism to ,form a stitch and causing thatstitch to be driven downwardly through the work material placedat-theouter end of the army It will be clear that material of widely varyingsizesand shapesmay be han-' dled, and may be received over the arm inany convenient position, a back gage 86 beingprovided upon the upperface of the arm to assist in the setting of the. work at a definitelocation.

The clincher operation is timed-ingprecletermined relation to the stitchforming and driving operation as shown in the sequential series ofviewsrepresented-in Figs. 5, Sand -'7. The initial formation of thestitch is shown in Fig. 5 with the legs being partially driven through.the sheet material and guided inwardly by the beveled portions 52, theslugsbeing indicatedat 9 L InFig. 6 the stitch has been completelyformed and driven downwardly, the downwardly extending legs being' bentinwardly as shown prior to contact with the upper surface of theclincher plunger and the slugs havebeen separated anddropped out of theway. In Fig. 7 the clincher plunger has completed its stroke and hasflattened the legs down. upon. the surfaceof the material, thus com-Such pleting the operation, the parts then being returned to theirinitial positionin preparationibr asubsequent cycle of. operation.

Adjustment of the arm either laterally or vertically does not disturbthe drive mechanism for operating the clincher and the accuratehorizontal relation of the arm is maintained throughout such adjustment.Likewise adjustment of the position of the die block assembly on the,arm does not affect the drive mechanism. The adjustment in the efiectivelength of the push rods is made: very easily and provides for adjustingfor the height of the arm and causing the plunger to moveto clinchingposition with the desireddegree of force, without requiring any otherchange in the driving connections.

As a specific example the machine was constructed to form a stitchhaving aspace between theinner sides of the legs of 1% inch using wireof .050 inch diameter and having a tensile strength of from 270,000 to320,000 pounds per square inch. The outermost extent of the groove atthe top of the tapered portion was the same as that of the outsidespacing of the legs of the stitch. Where the taper was about .020 to.025 inch on each side, or less, it was found that there was a tendencyfor the collapsing or folding back of the leg upon itself and a failureto turn the leg, inward sufficiently to be properly engaged by theplunger. On the other hand with a taper in excess of the diameter of thewire, 1. e. above about .050 inch, there was a tendency to produce anobjectionable curl inthe leg which was not entirely removed by theplunger and thus the clinch was not sufficiently fiat. Most satisfactoryresults were secured where the taper varied from about .030 to .040 inchat each side. With such a taper very satisfactory stitches were securedupon two hard metal sheets such as stainless steel or Duralumin each ofa thickness of approximately .040 inch. v A somewhat modifiedconstruction is shown in Figs. 9 to 12. In this construction the twodies I00 are bolted in place on die block IM and are provided withcooperating grooves I02 the inner ends of which are semi-circular incross section and are so mounted upon the die holder that the groovesextend for the full length of the stitch andhenceno tapered lead-in isprovided at the ends. The dies are relieved as shown at I03 with afrontportion I04 adapted to engage with the corresponding portion on theopposite die, to thereby close across the front of the dies for addedprotection. Also if desired the rear face of the die maybe removed asindicated at I05, this space with the relief provided at I03 afiording apassage through which any chips or slugs can be discharged. The plungeris shown at I06 and is of substantially the same cross length as thecombined extent of slots I02 so that it overlies the entire lower faceof the stitch and is rounded atits outer sides to fit closely within andto he guided by the slots I02. In order to providefor the in: wardturning of the ends of the stitch legs, the upper face of the plunger isprovided with upwardly raised ear portions I0? at opposite sidesthereof, these ears. making initial engaging contact with the legs ofthe stitch and turning the same inwardly toward each other. As thestroke of the plunger is completed, it bears against the entire lowerface of the stitch and with particular pressure against the endsthereof, to assure the clinching in a firm and tight manner. The radiusof curvature of the earsis approximately that of the bend, of the wireat thecorners, so.

that a flattening pressure is applied uniformly across the entire extentof the stitch. The upper surface of the plunger may be planetransversely, or may be grooved as shown at I08 in Fig. 12, to affordadditional guidin'g contact for the wire as the legs are beingflattened. Both the dies and the plunger are symmetrically formed sothat they can be reversed for additional use, as described above.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. In a wire stitching machine of the character described having a baseand an upwardly extending pedestal portion, forming a main frame for themachine and an overhanging head including a stitch forming mechanism,vertically extending ways on said frame, a clincher arm, means formounting said arm for vertical adjustment on said ways including gibsbearing respectively against said ways, and means for individuallyadjusting said gibs to provide for lateral shifting of said arm uponsaid ways to locate and secure the clincher mechanism in accuraterelation with respect to the stitch forming mechanism.

2. In a wire stitching machine of the character described having a baseand an upwardly extending pedestal portiondorming a main frame for themachine and an overhanging head including a stitch forming mechanism,vertically extending ways on said frame, a clincher arm, clinchermechanism carried by said arm, cans for mounting said arm for verticaladjustment on said ways, operating mechanism carried by said arm foreffecting actuation of said clincher mechanism, means operableseparately and independently of the vertical adjustment of said armforadjusting the extent of travel of said clincher mechanism, drive meansmounted on said frame, said drive means and said operating means havingcooperating parts maintained in predetermined driving relationthroughout the vertical travel of said arm to maintain a predeterminedsetting of said adjustable means throughout different positions ofvertical adjustment of said arm.

3. In a wire stitching machine of the character described having a baseand an upwardly extending pedestal portion, forming a main frame for themachine and an overhanging head including a stitch forming mechanism,vertically extending ways on said frame, a clincher arm, clinchermechanism carried by said arm, means for adjusting the extent of travelof said clinch er mechanism, means for mounting said arm for verticaladjustment on said ways, a push rod carried by said arm for actuatingsaid clincher mechanism, a drive rod mounted in said frame, one of saidrods having a relatively extended engaging surface providing formaintaining the operating engagement thereof and a predetermined settingof said adjusting mechanism substantially unaffected by the verticaltravel of said arm.

4. In a wire stitching machine of the character described having a baseand an upwardly extending pedestal portion, forming a main frame for themachine" and an overhanging head including a' stitch "forming mechanism,vertically extending ways on said frame, a clincher arm,

clincher mechanism operably carried by said arm including a clincherplunger, means for mounting said arm for vertical adjustment on saidways, means for adjusting said clincher mechani'sm to cause a greater orless travel of said clincher plunger to apply a predetermined c1inchingpressure to the ends of said stitch, means carried by said frame fordriving said clincher mechanism, and means for maintaining the drivingrelationship between said drive means and said clincher mechanism overthe range of vertical adjustment of said arm while maintaining apredetermined adjustment of the travel of said clincher plunger.

5. Clincher mechanism for a wire stitching machine comprising diemembers having a guide slot therein, a plunger movable in said slot toeffect the clinching of the stitch, an actuating mechanism connectedwith said plunger for moving said plunger through a normal cycle ofmovement within saidslot, and manual means for effecting thedisconnection of said actuating mechanism and said plunger to free saidplunger and provide for continued movement thereof in said slot to aposition where it is entirely withdrawn therefrom.

6. Clincher mechanism for a wire stitching machine comprising diemembers having a guide slot therein, a plunger movable in said slot toef feet the clinching of the stitch, an actuating mechanism for movingsaid plunger through a normal cycle of movement within said slotincluding a pin engaging said plunger to effect reciprocation thereof ina normal cycle or movement, and means for manually moving said pin to aposition beyond its normal range of reciprocating travel to effectdisengagement thereof from said plunger providing for free removal andreplacement of said plunger in said guide slot.

7. Clincher mechanism for a wire stitching machine comprising diemembers having a guide slot therein, a clincher plunger mounted forreciprocating travel in said slot to effect the clinching of the stitch,a bell crank having a pin projecting therefrom and engaging an aperturein said plunger, means for normally actuating said bell crank to effectsaid reciprocating travel of said plunger, and'means for modifying theaction of said actuating means to provide for movement of said bellcrank to a position beyond its normal range of travel such that said pinis withdrawn from the aperture in the plunger providing for directwithdrawal and replacement of the plunger in said guideslot.

8. Clincher mechanism for a wire stitching machine comprising diemembers having a guide slot therein, a clincher plunger mounted forreciprocating travel in said slot to effect the clinching of the stitch,a bell crank having a pin projecting therefrom and engaging an aperturein said plunger to effect said reciprocating travel of the plunger, apush rod for normally actuating said bell crank, and manual meansaccessible beneath said arm for moving said push rod and said bell crankto a position beyond the normal range of reciprocating travel thereofproviding for withdrawal of said pin from the aperture in the plungerreleasing the plunger for direct re-, moval and replacement in saidguide slot.

9. Clincher mechanism for a wire stitching machine comprising a dieholder, die members secured to said die holder in predeterminedcooperating relation and having guide slots for receiving the ends ofthe stiches as they are formed w and enclosing substantially half theperiphery of eacliend of the stitch, and a clincher plunger, movable inand guided'by said guide slots and movable'into engaging and flatteningrelation with the endsof said stitches, saidplung'er being symmetricallyformed atits opposite ends and adapted to be inserted in said guideslots in either of two relatively inverted positions'to "eife'ctclinching of the stitch and to provide'longer life.

"l; Clincher mechanism for a wire stitching machine'comprising'a dieblock, die members for receiving the legs of the stitclias it"is forcedthrough'the material and provided with guide slotsysaid die membershaving guide surfaces spaced apart a distance corresponding 'substan'tially to the outside spacing of the legs of the stitch and being formedwith portions having an ve lelaili ly te with res ect to each other;

in each: or which ,said guide slots, cooperate .to form legs of thestitch as slots to. clinch and flatten the legsofsaid stitch upon theface of thematerial, said'plungerbeing.

symmetrically formed to be received in two..rela-. .tivelyinvertedgPOfiitions within saidguide. slots to. provid for additional.wear thereon.

l nc e ..mechanismicr a wire stitching.

machinehaving a ,die, block comprising die mem.-.

bers. each having a guideeslot formed therein.ex-.. tending uniformlytothe. .upper. edge thereon means for amembling said die-members upon saidinward taper at each side less than the'thickne'ss of saidlegs andgreater than half the thickness thereof, said taper extending over'asubstantial vertical distance such that the legs ofsaid stitch areturned inwardly but"remain substantially. uncurled, and a clincherplunger movable in said guide slots to engage the inwardly turned legsof the stitch to flatten the same against the work material.

11; Clincher mechanism for a wire stitching die block in cooperatinrelationwith \s'aidire spective guide slots correlated. to. provide forireceiving the respective endsof thestitch in.sub-. stantialparallelrelationas the same is formed,- a clincher plunger movable intoclinching.v posi-.-.

tion within said guidegslots.to..flatten.the.legs of said stitch upo ntheface of the material, said guide slots and. saidplunger having alength substantially the same as the outside. length of the stitchitself, said plunger. having upwardly.ex-

guide slots to engage the inwardlyturned'legs of the stitch to flattenthesam'e against the work material. 12. In clincher mechanism for a wirestitching machine "having a die block, a pair of die memk ber'sforreceiving the ends of the wire as the stitch is forced throughthematerial, each of said die membershaving a guide slot therein forreceiving the advancing, end or the "leg of the stitch while providingsupport for substantially the outerhalf of the periphery thereof, eachof said die members being symmetrically formed'at opposite ends with asimilar guide slot to provide forassemblyof said die members in invertedpo- .sitio'n to afford additional wear" thereon.

13; In clincher mechanism for a wire stitching machine having a dieblock, a pair of die memhers adapted to be secured'to said die block ineither of-two relatively inverted positions; said dien'ieinbers eachhaving a guide slot iorrned therein andsymmetrically positioned toprovide. for assembly of said die members in two positionsrelatively'inverted with respect'to each other in each of which saidguideslots cooperate to "form a diefor receiving the opposite ends ofthe legs of the stitch as said legs are forced through the material tobe stitched, and a" clincher plunger mounted for reciprocatingtravel insaid guide slots to clinch and flatten the legs of said upon the face ofthe'work material; 7

14. In clincher mechanism for a wire stitching machine having adiebloc'k, a pair of die mend-J hers-adapted to besecuredto saiddieblock; in

stitch either oftWb relatively inverted positionais'aid l h h ktheforces of said spring means. fordisplacing die 'members each "having'a" guide slot formed:

therein and symmetricallypositioned to provide 7 1 for assembly: ofsa'lid jdie inernbers in "two pbsi- 10 *Ji i? j." i v i tending earsadjacent its'opposite ends, to receive the ends of the legs and toinitiatea bend therein.

in preparation for the flattening thereof against the material and toapply flattening pressure across the entire extent of the stitch.

l6. Clincher mechanism for a wire stitching machine having a dieblockcomprising die members each having a guide .slot formed therein,

means for assembling said diemembers upon said "die block in cooperatingrelation with said re.-

spective guide slots correlated to provide for receiving the respectiveends ofthe stitch as the same is formed, a clincher plunger movable intoclinching position within; said guide slot to fiat-.

ten the legs of said stitch upon the face ofthe material, said clincherplunger having a work engaging endadapted to, engage the legs of saidstitch and to pressthe same fiat against the material, said plunger alsohaving a part located forwardly of the plane of said guideslots andprojecting above said work engaging end to prevent forward displacingmovementof the ends jof the. legs and to restrain said legs within.the'plane of thestitch.

17. Clincher mechanism for a wire stitching machin comprising a. dievblock, means carried by said die block forming die members for receivingthe ends. of theiwire stitches the'stitch is forced through thematerial, said die block hav-.

ingair snpply n eans in line witha part of each leg of the stitch whichprojects through the work material, and mean for supplying .air pressureto said air supply means to discharge air jets therefromdirectly againstthe chips formed .by

each leg of the stitch to effect removal thereof.

18; In a stapling machine a base carrying a,

stationary die,'a staple clinchin die movable relative to saidstationary die, a rockerpivotally mounted upon said base and having aknub portion extending into a recessed portion of said clinching'dieforfl'crariking' the lattertoinove in directions'transversely of the.direction. of. exten; V V sion of said knub portion, spring meanstending to bias said rocker away from staple clinching.

procuring positionj and ,meansTadapted to'be l v manually operated, to'rotate said 'roclre'ifagainst,v

nectionswithsaid diejrecessedipoi'tioni ie iece na he .oppcsite. ends.of the I S d legsareforced through.

the material to be stitched, and a clincher, plung- "er mountedforreciprecating travel in said guide 19. In a stapling machine, a base,a stationary die mounted on said base, a staple clinching die movablerelative to said stationary die, a rocker pivotally mounted upon saidbase and having a knub portion extending into operating connection witha recessed portion of said clinching die, spring means tending to biassaid rocker away from staple clinching position, and means carried bysaid rocker adapted to be manually operated upon to actuate said rockeragainst the forces 10 of said spring means for rotating said rocker knubportion out of connected relation with respect to said clinching diemember, whereby said movable die member may be freed of connection tosaid rocker to permit removal of said 15 die from said machine.

WILLIAM R. SPILLER. ROBERT J NIEDERHAUSER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Patent No. 2,424,717.

Certificate of Correction July 29, 1947. WILLIAM R. SPILLER ET AL.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows: Column 5,line 38, for ball read bell; column 10, line 74, for stiches readstitches; column 14, after line 16, add the following reference1,761,586 Price June 8,1930

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 7th day of October, A. D. 1947.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

